The series hinges on the story of a sergeant in the 6th Airborne Division, a veteran of Arnhem who saw the liberation of Belsen concentration camp, who arrives in Palestine in September 1945 with his unit. In the first episode a British intelligence officer explains to the new troops that Jews are flooding into Palestine in fulfilment of "a promise made by God". This influx is troubling the Arabs who have lived in Palestine "since time immemorial". The job of the British, he announces, is to keep the two sides apart. The paratroopers are like the "meat in a sandwich".

But, hold on a minute. It was the British who promised Palestine to the Jews as a Jewish national home in 1917 and the British who flooded Palestine with troops to protect a vital piece of imperial real estate in 1945. Zionist aspirations, which the British had fostered, and Palestinian Arab opposition to them, were a problem only in so far as they complicated British planning for the cold war.

The sergeant, through whose eyes we see the debacle unfold, also witnesses the massacre of Palestinian Arabs at the village of Deir Yassin in April 1948. By this time his allegiances are with the Arab population. On the eve of the British evacuation from Haifa he pleads with his superiors to use the army's firepower to prevent the Jewish forces from overwhelming and driving out the Arab inhabitants. He protests that Britain can't just walk away after "we've been here for 30 years keeping them apart".

This is the central conceit, and deceit, of Kosminsky's epic. The British were in Palestine for their own interests and when it no longer suited them they left. To conceal this fact he has to perpetrate a massive historical distortion. Although The Promise is insufferably didactic, no one mentions the Balfour declaration. Yet it was the British foreign secretary, AJ Balfour, who informed the English Zionist Federation in November 1917 that "His Majesty's government view with favour the establishment in Palestine of a national home for the Jewish people, and will use their best endeavours to facilitate the achievement of this object". This was the only promise that mattered because it had the force of international law. It was subsequently incorporated into the mandate that the League of Nations gave Britain to authorise its possession of Palestine. In 1922 parliament voted to accept the mandate and all that went with it.

These diplomatic moves allowed Jews to begin building a state in what they saw as their ancestral land. But this had less to do with what they believed and more to do with what the British wanted. Britain had invaded Palestine in 1916 to protect the Suez canal from the Turks and once they had conquered it wanted a pretext for remaining. They also wanted to keep out their imperial rivals, the French, and thwart Arab hopes of nationhood. The Balfour declaration conveniently negated earlier promises to Arab nationalists to assist the establishment of an Arab state in territory to be liberated from the Turks.

During the second world war Palestine was an essential military base, second only in importance to Egypt. When Rommel threatened Alexandria and Cairo in 1942, Haifa was the back-up port for the Royal Navy. Sarafand in central Palestine was one of the largest British army bases in the region. Above all, oil was piped from southern Iraq to the refineries at Haifa to fuel the Desert Rats. Palestine's geo-strategic importance increased still further after the defeat of Germany. British military planners now feared a Soviet thrust into the Middle East. They needed Haifa for the navy, Sarafand for the army, and the Ramat David airbase in Galilee from which heavy bombers of the RAF could reach southern Russia. Pressure from Arab nationalists in Egypt to close the British bases in the Nile delta added immeasurably to the value of Palestine.

This was why the British beefed up the garrison there. The paratroops were not sent to separate Jews and Arabs. They joined the 1st Infantry Division as Britain's strategic reserve in the Middle East. When the Zionist movement launched its campaign to drive the British out, British troops were deployed to suppress a Jewish insurrection that threatened Britain's route to India, its oil supplies, and its entire regional strategy. Jews and Arabs were just an irritant in a much bigger imperial conflict. The tragedy for both lay in their expendability. When the costs outweighed the benefits of staying in Palestine, the British pulled out with little concern about what happened next. We are still living with the consequences, some of which are depicted in the present-day sequences of The Promise.

However, in Kosminsky's version we are absolved of any responsibility for what is happening there. He has turned the British, who were the chief architects of the Palestine tragedy, into its prime victims. The Promise is a glossy exercise in self-exculpation. Someone must be responsible, though, and the way he rewrites history that can only be the Jews. Ultimately, Kosminsky turns a three-sided conflict into a one-sided rant.

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